any one have any photos of or advice on building a small post cure oven?
i was thinking of a plywood box lined with concrete backer board and space heaters on each end hooked to a thermostat…
i have strange fire worries due to childhood events so i want to make it safe so i can sleep at night…
i was thinking the heat would have to be indirect, that is not blowing directly onto the board so that everything would cure up evenly…
any web links to supplies? suggestions… thanks in advance.
I’m not exactly sure what you’re after, but here’s the oven I used for a couple of DHP boards. You can see the oven thermometer in the foreground, and the hole for the hair dryer in the back of the box. Not strictly fireproof, but you could set it up outside.
The photo of the insulated box is a great one. The cost is low, and you can run fairly high temp’s. I built a walk in oven on the same principle, and run the temp’s up in the 160 to 180 range for 4 to 5 hours with no problems. For long duration heating a space heater may “give up” but at lower temp’s should work fine. I suggest finding a heater with a closed element to minimize the fire hazard. Good luck!!!
On an open section of wall, make some regular horizontal board holders (2x4’s with 1" dowels, 24" apart vertically). Leave 36" high space at bottom. Frame area according to board sizes with 2x4’s. Attach rigid faced insulation panels (Home Depot) to sides and top, leave front open. Use insulation panels on front, but attach with velcro or hooks so you can lift off. Use small (around 800 BTU) space heater with fan at bottom (plug in outside box), and check upper board using a non-contact thermometer (Harbor Freight $15) after about 15 min. You want about 95 F at bottom of top board. Once you see that temp, put the front panel back on, run the heater for about 5 min more and then shut off and let it soak. How often you need to run the heater depends on the room temp; this timing is my experience with a 15’ long x 8’ high x 3’ deep box at 70F ambient holding 5 LB or SUP. If your ambient temp is very low, you’ll need to seal the box very well. You want a 95F soak for at least 12 hours, more or less. Be sure that you have an opening on the board (if curing lams) or vent it if finished. If you choose to go the thermostat route, use the thermometer to be sure you know the skin temp on the top board. The good thing about this design is that it’s an enclosed board rack when not in use.
Hi - I rigged up a box using the foil coated polyurethane foam insulation panels from Home Depot. I held it all together with shish-ka-bob skewers while the spray can insulation foam cured. The spray foam made pretty good glue as long as I removed the foil along the glue joints. Two light bulb fixtures with various watt bulbs create the heat. A simple digital probe thermometer is poked through the insulation panel to monitor temperature inside. When the outside temperatures are below freezing I can get this box over 100 degrees easily. A small fan helps prevent hot spots.
PS - It is essentially the same as OregonPeter's.
I used to use a blank box with a small heater on one end and cut a slit on the other end for airflow. Cheapest effective solution.
[img_assist|nid=1043323|title=Heater|desc=|link=none|align=left|width=100|height=75][img_assist|nid=1043322|title=Blank Box Epoxy Postcure|desc=|link=none|align=left|width=100|height=75]
~Brian
I like it Brian. My problem is no place to store a proper box. Your temp soln could work for me.
This one breaks down and stores easily…
Made mine wIth a few bamboo sticks and a roll of bubble wrap and just stick in an electric heater. Just used for curing epoxy. Works great.
Made mine wIth a few bamboo sticks and a roll of bubble wrap and just stick in an electric heater. Just used for curing epoxy. Works great.
Cheers
Rich
Www.thirdshade.com
Here is an auto temp device I just got from Amazon. I built the box from AC insulation sheets. I almost over cooked my first attempt and decided that since I get distracted easily, which reminds me we are supposed to have waves this weekend in Brevard. Wait. Since I get distracted easily with other porjects, I needed something to monitor and control the temperature. $31.00.
Thanks for the ideas.
I’ve been considering a low temp ‘kiln’ to suck the moisture out of a shaped Cedar HWS before sealing the exterior with epoxy, more so than a post glassing cure, but of course there is overlap. My glassing environment can also never be made dust free, so lowering a box over my table would be desirable as well.
Do All epoxies benefit from post curing? I was reading up on System3 Silvertip laminating resin and they say that when used with their slow hardener can be
" can be post-cured for even greater high temperature resistance and elevated mechanical specifications."
Which is not a claim they make of their other epoxies.
Time to cure is not really a concern of mine, but for the added time at which dust can settle and affect the finish, but Stronger mechanical properties and perhaps high temperature resistance does have appeal.
i have a small 200 watt electric heater, that i have used on a router speed controller to dial its heat output back. I used The RSC on a 1600 watt hairdrier as an experiment, but the On off switch melted.
On dissection and inspection of the switch, it was heavily carboned up and its failure ‘might’ not be related to the RSC operation
As for internal air circulation I have many 12v computer fans of varying CFM, and can put a filter on them and the intake of the 200 watt heater as well.
The filter should be a 5 sided ‘box’ well away from the back of the fan impeller for more surface area and less restriction. I use a stapler and some filter media meant for installing in Hvac vents available at home depot. ‘register vent filters’ search term
Greg, that temp control looks awesome. Now all you need is a timer to shut the whole works off after a few hours in case you get really distracted.
